1. Field of the Invention
The present invention relates to a film cassette opener for unloading a film from a film cassette and/or loading a film in the film cassette.
2. Description of the Related Art
In each of the cases where such a film cassette opener is used to automatically load an unexposed X-ray film taken out of a magazine containing a plurality of unexposed film sheets therein, in an X-ray film cassette and where such an opener is used to unload an exposed X-ray film from the X-ray film cassette, the cassette is transported along a path of cassette travel within the opener to a predetermined position at which an X-ray film is loaded or unloaded. When the X-ray film cassette reaches this position, a lid of the cassette is opened in a state wherein ambient light is blocked. Accordingly, this type of film cassette opener is commonly arranged in such a manner that, in order to transport the X-ray film cassette to the film unloading (loading) position, a pair of opposite sides of the X-ray film cassette is held and transported along the path of travel to the position at which the X-ray film is loaded or unloaded. The unloaded film sheet is then transported to a film developing machine or an empty film magazine to store the exposed film sheets.
Japanese Patent Laid-open No. 205439/1985 proposes a structure in which a plurality of rollers are employed to hold the opposite ends of the X-ray film cassette.
In this known structure using a plurality of rollers, however, while the X-ray film cassette is being transported along the path of travel, the cassette is often moved in a zigzag manner. In addition, this structure involves disadvantage in that, since the rollers are partially separated from the opposite sides of the cassette, it may be difficult to positively transport the cassette in a desired direction.
Furthermore, when the rollers abuts against the corresponding sides of the cassette by an insufficient level of pressure, slips may occur between the rollers and the corresponding sides of the cassette to cause the roller to rotate idly.